New motor car registrations were down 54 percent to 1,464 in December from a year earlier, but were up from the low of 1,073 hit in September.
Three wheeler registrations were down 44 percent to 7,000 units. After falling as low as 3,533 units in May 2012, 3-wheeler registrations recovered to 8,060 in November.
Small (hand) tractor sales were down 56 percent to 886.
New light truck ownership were back at levels seen in 2011, before a balance of payments crisis hit Sri Lanka's monetary system.
Light truck registrations were down 6 percent to 1,780 in December from a year earlier.
Sri Lanka ran into a balance of payments crisis in mid 2011 when large volumes of credit taken to manipulate energy tariffs were accommodated with central bank credit.
In February 2012, energy tariffs and interest rates were hiked and the rupee was floated to allow the exchange rate to respond to monetary policy.
Taxes on cars, three wheelers and motor cars were jacked up.
New registrations of Maruti and Suzuki, makes which mostly sell small cars were down 64 percent in December to 267. Luxury BMW sales rose 161 percent to 55 units.
BMWs are believed to be imported on tax-slashed permits given to state workers. There is an active secondary market it tax slashed permits.